RESUMO
Heterobifunctional chimeric degraders are a class of ligands that recruit target proteins to E3 ubiquitin ligases to drive compound-dependent protein degradation. Advancing from initial chemical tools, protein degraders represent a mechanism of growing interest in drug discovery. Critical to the mechanism of action is the formation of a ternary complex between the target, degrader and E3 ligase to promote ubiquitination and subsequent degradation. However, limited insights into ternary complex structures exist, including a near absence of studies on one of the most widely co-opted E3s, cellular inhibitor of apoptosis 1 (cIAP1). In this work, we use a combination of biochemical, biophysical and structural studies to characterize degrader-mediated ternary complexes of Bruton's tyrosine kinase and cIAP1. Our results reveal new insights from unique ternary complex structures and show that increased ternary complex stability or rigidity need not always correlate with increased degradation efficiency.
Assuntos
Tirosina Quinase da Agamaglobulinemia/genética , Proteínas Inibidoras de Apoptose/genética , Cromatografia em Gel , Reagentes de Ligações Cruzadas , Humanos , Cinética , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Conformação Proteica , Proteólise , Espectrometria de Massas por Ionização por Electrospray , Ubiquitina-Proteína Ligases , Ubiquitinação , Difração de Raios XRESUMO
Proteolysis targeting chimeras (PROTACs) are heterobifunctional small molecules that simultaneously bind to a target protein and an E3 ligase, thereby leading to ubiquitination and subsequent degradation of the target. They present an exciting opportunity to modulate proteins in a manner independent of enzymatic or signaling activity. As such, they have recently emerged as an attractive mechanism to explore previously "undruggable" targets. Despite this interest, fundamental questions remain regarding the parameters most critical for achieving potency and selectivity. Here we employ a series of biochemical and cellular techniques to investigate requirements for efficient knockdown of Bruton's tyrosine kinase (BTK), a nonreceptor tyrosine kinase essential for B cell maturation. Members of an 11-compound PROTAC library were investigated for their ability to form binary and ternary complexes with BTK and cereblon (CRBN, an E3 ligase component). Results were extended to measure effects on BTK-CRBN cooperative interactions as well as in vitro and in vivo BTK degradation. Our data show that alleviation of steric clashes between BTK and CRBN by modulating PROTAC linker length within this chemical series allows potent BTK degradation in the absence of thermodynamic cooperativity.
Assuntos
Proteínas Tirosina Quinases/metabolismo , Proteólise , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Tirosina Quinase da Agamaglobulinemia , Animais , Células Cultivadas , Ligantes , Poliubiquitina/metabolismo , Ratos , TermodinâmicaRESUMO
The drugable proteome is limited by the number of functional binding sites that can bind small molecules and respond with a therapeutic effect. Orthosteric and allosteric modulators of enzyme function or receptor signaling are well-established mechanisms of drug action. Drugs that perturb protein-protein interactions have only recently been launched. This approach is more difficult due to the extensive contact surfaces that must be perturbed antagonistically. Compounds that promote novel protein-protein interactions promise to dramatically expand opportunities for therapeutic intervention. This approach is precedented with natural products (rapamycin, FK506, sanglifehrin A), synthetic small molecules (thalidomide and IMiD derivatives) and indisulam analogues.
Assuntos
Adesivos/farmacologia , Produtos Biológicos/farmacologia , Regulação Alostérica/efeitos dos fármacos , Descoberta de Drogas , Humanos , Ligantes , Ligação Proteica , Proteólise , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/metabolismoRESUMO
The synthesis and antibacterial activity of heterocyclic methylsulfone hydroxamates is presented. Compounds in this series are potent inhibitors of the LpxC enzyme, a key enzyme involved in the production of lipopolysaccharide (LPS) found in the outer membrane of Gram-negative bacteria. SAR evaluation of compounds in this series revealed analogs with potent antibacterial activity against challenging Gram-negative species such as Pseudomonas aeruginosa and Klebsiella pneumoniae.
Assuntos
Amidoidrolases/antagonistas & inibidores , Antibacterianos/química , Inibidores Enzimáticos/química , Bactérias Gram-Negativas/efeitos dos fármacos , Ácidos Hidroxâmicos/química , Amidoidrolases/metabolismo , Antibacterianos/síntese química , Antibacterianos/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Compostos Heterocíclicos/química , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , Relação Estrutura-Atividade , Sulfonas/químicaRESUMO
Novel siderophore-linked monobactams with in vitro and in vivo anti-microbial activity against MDR Gram-negative pathogens are described.
Assuntos
Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Monobactamas/farmacologia , Animais , Sítios de Ligação/efeitos dos fármacos , Proteínas Sanguíneas/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Monobactamas/síntese química , Monobactamas/química , Ratos , Relação Estrutura-AtividadeRESUMO
To facilitate a drug discovery project, we needed to develop a robust asymmetric synthesis of (2S,5S)-5-substituted-azepane-2-carboxylate derivatives. Two key requirements for the synthesis were flexibility for elaboration at C5 and suitability for large scale preparation. To this end we have successfully developed a scalable asymmetric synthesis of these derivatives that starts with known hydroxy-ketone 8. The key step features an oxidative cleavage of aza-bicyclo[3.2.2]nonene 14, which simultaneously generates the C2 and C5 substituents in a stereoselective manner.
Assuntos
Ácidos Carboxílicos/química , Ácidos Carboxílicos/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Descoberta de Drogas , Cetonas/químicaRESUMO
High-throughput experimentation (HTE) has emerged as an important tool in drug discovery, providing a platform for preparing large compound libraries and enabling swift reaction screening over wide-ranging conditions. Recent advances in automated high-density, material-sparing HTE have necessitated the development of rapid analytics with sensitivity and resolution sufficient to identify products and/or assess reaction performance in a timely and data-rich manner. Combination of an ultrathroughput (UT) reader platform with Acoustic Droplet Ejection-Open Port Interface-Mass Spectrometry (ADE-OPI-MS) provides the requisite speed and sensitivity. Herein, we report the application of ADE-OPI-MS to HTE in the areas of parallel medicinal chemistry and reaction screening.
RESUMO
Explorations in the pyrimidinetrione series of MMP-13 inhibitors led to the discovery of a series of spiro-fused compounds that are potent and selective inhibitors of MMP-13. While other spiro-fused motifs are hydrolytically unstable, presumably due to electronic destabilization of the pyrimidinetrione ring, the spiropyrrolidine series does not share this liability. Greater than 100-fold selectivity versus other MMP family members was achieved by incorporation of an extended aryl-heteroaryl P1'group. When dosed as the sodium salt, these compounds displayed excellent oral absorption and pharmacokinetic properties. Despite the selectivity, a representative of this series produced fibroplasia in a 14 day rat study.
Assuntos
Inibidores de Metaloproteinases de Matriz , Inibidores de Proteases/química , Pirimidinas/química , Pirrolidinas/química , Compostos de Espiro/química , Animais , Estabilidade Enzimática/efeitos dos fármacos , Metaloproteinase 13 da Matriz/metabolismo , Inibidores de Proteases/farmacologia , Pirimidinas/farmacologia , Pirrolidinas/farmacologia , Ratos , Compostos de Espiro/farmacologia , Relação Estrutura-AtividadeRESUMO
Signaling through vascular endothelial growth factor (VEGF) receptors (VEGFRs) is a key pathway initiating endothelial cell proliferation and migration resulting in angiogenesis, a requirement for human tumor growth and metastasis. Abrogation of signaling through VEGFR by a variety of approaches has been demonstrated to inhibit angiogenesis and tumor growth. Small molecule inhibitors of VEGFR tyrosine kinase have been shown to inhibit angiogenesis, inhibit tumor growth, and prevent metastases. Our goal was to discover and characterize an p.o. active VEGFR-2 small molecule inhibitor. A novel isothiazole, CP-547,632, was identified as a potent inhibitor of the VEGFR-2 and basic fibroblast growth factor (FGF) kinases (IC(50) = 11 and 9 nM, respectively). It is selective relative to epidermal growth factor receptor, platelet-derived growth factor beta, and other related TKs. It also inhibits VEGF-stimulated autophosphorylation of VEGFR-2 in a whole cell assay with an IC(50) value of 6 nM. After oral administration of CP-547,632 to mice bearing NIH3T3/H-ras tumors, VEGFR-2 phosphorylation in tumors was inhibited in a dose-dependent fashion (EC(50) = 590 ng/ml). These plasma concentrations correlated well with the observed concentrations of the compound necessary to inhibit VEGF-induced corneal angiogenesis in BALB/c mice. A sponge angiogenesis assay was used to directly compare the inhibitory activities of CP-547,632 against FGF receptor 2 or VEGFR-2; this compound potently inhibits both basic FGF and VEGF-induced angiogenesis in vivo. The antitumor efficacy of this agent was evaluated after once daily p.o. administration to athymic mice bearing human xenografts and resulted in as much as 85% tumor growth inhibition. CP-547,632 is a well-tolerated, orally-bioavailable inhibitor presently under clinical investigation for the treatment of human malignancies.
Assuntos
Inibidores Enzimáticos/farmacologia , Tiazóis/farmacologia , Ureia/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/enzimologia , Inibidores Enzimáticos/farmacocinética , Feminino , Humanos , Cinética , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Nus , Células NIH 3T3 , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Ureia/análogos & derivados , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Interest in drugs that covalently modify their target is driven by the desire for enhanced efficacy that can result from the silencing of enzymatic activity until protein resynthesis can occur, along with the potential for increased selectivity by targeting uniquely positioned nucleophilic residues in the protein. However, covalent approaches carry additional risk for toxicities or hypersensitivity reactions that can result from covalent modification of unintended targets. Here we describe methods for measuring the reactivity of covalent reactive groups (CRGs) with a biologically relevant nucleophile, glutathione (GSH), along with kinetic data for a broad array of electrophiles. We also describe a computational method for predicting electrophilic reactivity, which taken together can be applied to the prospective design of thiol-reactive covalent inhibitors.
Assuntos
Inibidores Enzimáticos/química , Glutationa/química , Desenho de Fármacos , Glutationa/metabolismo , Humanos , Cinética , Espectrometria de Massas , Ressonância Magnética Nuclear Biomolecular , Preparações Farmacêuticas/químicaRESUMO
We report novel polymyxin analogues with improved antibacterial in vitro potency against polymyxin resistant recent clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa . In addition, a human renal cell in vitro assay (hRPTEC) was used to inform structure-toxicity relationships and further differentiate analogues. Replacement of the Dab-3 residue with a Dap-3 in combination with a relatively polar 6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl side chain as a fatty acyl replacement yielded analogue 5x, which demonstrated an improved in vitro antimicrobial and renal cytotoxicity profiles relative to polymyxin B (PMB). However, in vivo PK/PD comparison of 5x and PMB in a murine neutropenic thigh model against P. aeruginosa strains with matched MICs showed that 5x was inferior to PMB in vivo, suggesting a lack of improved therapeutic index in spite of apparent in vitro advantages.
Assuntos
Infecção Hospitalar/tratamento farmacológico , Descoberta de Drogas , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Polimixinas/química , Polimixinas/farmacologia , beta-Alanina/análogos & derivados , Animais , Antibacterianos/química , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Cães , Feminino , Bactérias Gram-Negativas/fisiologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Polimixinas/farmacocinética , Polimixinas/toxicidade , Ratos , beta-Alanina/químicaRESUMO
Herein we describe the structure-aided design and synthesis of a series of pyridone-conjugated monobactam analogues with in vitro antibacterial activity against clinically relevant Gram-negative species including Pseudomonas aeruginosa , Klebsiella pneumoniae , and Escherichia coli . Rat pharmacokinetic studies with compound 17 demonstrate low clearance and low plasma protein binding. In addition, evidence is provided for a number of analogues suggesting that the siderophore receptors PiuA and PirA play a role in drug uptake in P. aeruginosa strain PAO1.
Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Monobactamas/farmacologia , Piridonas/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacocinética , Escherichia coli/efeitos dos fármacos , Concentração Inibidora 50 , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Testes de Sensibilidade Microbiana , Estrutura Molecular , Monobactamas/química , Monobactamas/farmacocinética , Pseudomonas aeruginosa/efeitos dos fármacos , Piridonas/química , Piridonas/farmacocinética , Ratos , Ratos WistarRESUMO
The synthesis and biological activity of a new series of LpxC inhibitors represented by pyridone methylsulfone hydroxamate 2a is presented. Members of this series have improved solubility and free fraction when compared to compounds in the previously described biphenyl methylsulfone hydroxamate series, and they maintain superior Gram-negative antibacterial activity to comparator agents.
Assuntos
Amidoidrolases/antagonistas & inibidores , Antibacterianos/síntese química , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Ácidos Hidroxâmicos/síntese química , Piridonas/síntese química , Ácidos Sulfônicos/síntese química , Animais , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Cristalografia por Raios X , Humanos , Ácidos Hidroxâmicos/farmacocinética , Ácidos Hidroxâmicos/farmacologia , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Conformação Proteica , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , Piridonas/farmacocinética , Piridonas/farmacologia , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Ácidos Sulfônicos/farmacocinética , Ácidos Sulfônicos/farmacologiaRESUMO
In this paper, we present the synthesis and SAR as well as selectivity, pharmacokinetic, and infection model data for representative analogues of a novel series of potent antibacterial LpxC inhibitors represented by hydroxamic acid.
Assuntos
Amidoidrolases/antagonistas & inibidores , Antibacterianos/síntese química , Compostos de Bifenilo/síntese química , Ácidos Hidroxâmicos/síntese química , Éteres Fenílicos/síntese química , Infecções por Pseudomonas/tratamento farmacológico , Sulfetos/síntese química , Sulfonas/síntese química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Domínio Catalítico , Cristalografia por Raios X , Farmacorresistência Bacteriana , Ligação de Hidrogênio , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/farmacologia , Camundongos , Modelos Moleculares , Conformação Molecular , Éteres Fenílicos/química , Éteres Fenílicos/farmacologia , Pseudomonas aeruginosa , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Sulfetos/química , Sulfetos/farmacologia , Sulfonas/química , Sulfonas/farmacologiaRESUMO
Linezolid (Zyvox) is the first member of an entirely new class of antibiotics to reach the market in over 35 years; it was approved for use in 2000. A member of the oxazolidinone class of antibiotics, linezolid is highly effective for the treatment of serious Gram-positive infections and has activity that compares favorably with vancomycin for most clinically relevant pathogens. Zyvox is approved for use against serious Gram-positive infections, including those caused by Streptococcus pneumoniae, and the very challenging methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium organisms. Zyvox inhibits bacterial protein synthesis by binding to 23S rRNA in the catalytic site of the 50S ribosome. It can be administered both orally and intravenously and has good tissue distribution. Recent results have demonstrated that oxazolidinone analogs related to linezolid are effective in treating pulmonary tuberculosis caused by resistant Mycobacterium tuberculosis in animal infection models and suggest additional new therapeutic applications for these antibiotics.
Assuntos
Acetamidas/uso terapêutico , Antibacterianos/uso terapêutico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Oxazolidinonas/uso terapêutico , Acetamidas/síntese química , Acetamidas/farmacocinética , Animais , Antibacterianos/síntese química , Antibacterianos/farmacocinética , Descoberta de Drogas/tendências , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/fisiologia , Humanos , Linezolida , Modelos Biológicos , Modelos Moleculares , Oxazolidinonas/síntese química , Oxazolidinonas/classificação , Oxazolidinonas/farmacocinéticaRESUMO
A novel series of monocarbam compounds exhibiting promising antibacterial activity against multidrug resistant Gram-negative microorganisms is reported, along with the synthesis of one such molecule MC-1 (1). Also reported are structure-activity relationships associated with the in vitro and in vivo efficacy of 1 and related analogues in addition to the hydrolytic stability of such compounds and possible implications thereof.
RESUMO
Respiratory tract bacterial strains are becoming increasingly resistant to currently marketed macrolide antibiotics. The current alternative telithromycin (1) from the newer ketolide class of macrolides addresses resistance but is hampered by serious safety concerns, hepatotoxicity in particular. We have discovered a novel series of azetidinyl ketolides that focus on mitigation of hepatotoxicity by minimizing hepatic turnover and time-dependent inactivation of CYP3A isoforms in the liver without compromising the potency and efficacy of 1.
Assuntos
Azetidinas/química , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Cetolídeos/química , Cetolídeos/farmacologia , Infecções Respiratórias/tratamento farmacológico , Animais , Bactérias/efeitos dos fármacos , Infecções Comunitárias Adquiridas/tratamento farmacológico , Suscetibilidade a Doenças , Descoberta de Drogas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Cetolídeos/efeitos adversos , Cetolídeos/síntese química , Cetolídeos/uso terapêutico , Camundongos , Testes de Sensibilidade MicrobianaRESUMO
The asymmetric synthesis of (2R,3R)-3-methyl-3-hydroxypipecolic acid, a key intermediate in the synthesis of dual MMP-13/aggrecanase inhibitors, is described. The title compound is prepared in seven steps with an overall yield of 41% starting from geraniol. Key steps in the synthesis include Sharpless asymmetric epoxidation, which establishes the chiral centers, and a one-pot oxidative olefin cleavage/reductive amination sequence that closes the piperidine ring.
Assuntos
Ácidos Pipecólicos/síntese química , Terpenos/química , Monoterpenos Acíclicos , Hidrólise , Estrutura Molecular , Ozônio/química , Ácidos Pipecólicos/química , EstereoisomerismoRESUMO
The design, synthesis, and biological evaluation of potent inhibitors of the TrkA kinase is presented. A homology model is created to aid in the enhancement of potency and selectivity of isothiazole inhibitors found during a high-throughput screen. Three different syntheses are utilized to make diverse analogs within this series. Aminoheterocycles are found to be good urea surrogates, whereas bicyclic substituents on the C3 thio group were found to be extremely potent TrkA inhibitors in kinase and cell assays.
Assuntos
Simulação por Computador , Inibidores Enzimáticos , Receptor trkA/antagonistas & inibidores , Tiazóis , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química , Tiazóis/farmacologiaRESUMO
A series of pipecolic hydroxamate inhibitors of MMP-13 and aggrecanase was discovered based on screening known inhibitors of TNF-alpha converting enzyme (TACE). Potency versus aggrecanase was optimized by modification of the benzyloxyarylsulfonamide group. Incorporation of geminal alkyl substitution at the 3-position of the piperidine ring improved metabolic stability, presumably by increasing steric hindrance around the metabolically labile hydroxamic acid. This modification also resulted in dramatic improvement of aggrecanase activity with a slight reduction in selectivity versus MMP-1. Synthesis, structure activity relationships, and strategies to reduce metabolic clearance are described.